thyroid cancer thyroid cancer
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THYROID CANCERTHYROID CANCER
Mai H. Nguyen, M.D.Francis B. Quinn, M.D.
Dec. 04, 2002
HistoryHistory
! 1812: Gay-Lussac discovered iodine as a cause of goiter.
! 1833: Boussingault prescribed iodized salt for prevention and treatment of goiter.
! 1836: T.W.King presented anatomical descriptions of thyroid gland.
! 1870: Fagge described sporadic and congenital cretinism.
History History
! 1882 - 1917: Theodor Kocher (Bern) introduced techniques of thyroidectomy(>5000 cases). His mortality rate at the end of 19th century is as low as 1.8%
! 1880s: Billroth suggested bilateral partial thyroidectomy to prevent hypothyroidism.
HistoryHistory
! 1880: Williams S. Halsted: developed his thyroidectomy techniques in the US.
! Thyroid cancer was first described by Halsted by the terms “sarcomatousdegeneration”, “thyroid tumor” or “thyroid cancer cells”
EmbryologyEmbryology
• 4th week: thyroid gland appears.• 5th week: break down of the thyroglossal
duct, thyroid gland continue descending• 7th week: thyroid gland migrates to its
position, anterior to the trachea• 10th week: thyroglossal duct disappears
AnatomyAnatomy
! Locate deep to the sternohyoid muscle, from level C5 to T1 vertebrae or anterior to the 2nd and 3rd tracheal rings.
! Thyroid gland is attached to the trachea by the lateral suspensory (Berry) ligaments.
AnatomyAnatomy
! Thyroid gland includes 2 lobes and isthmus.
! Isthmus: conical or pyramidal shape.
AnatomyAnatomy! Blood supply: sup. & inf.
thyroid arteries! Anatomy variant: thyroid
ima artery, in 1.5% to 12%, in front of the trachea.
! Lymph vessels: drain to prelaryngeal, pretrachealand paratracheal nodes.
! Innervation: superior, middle, and inferior sympathetic ganglia.
AnatomyAnatomy
! Venous supply– Superior and middle
thyroid v. drain into the IJ
– Inferior thyroid v. drains into the brachiocephalic trunk
AnatomyAnatomy--Recurrent Laryngeal Nerve Recurrent Laryngeal Nerve (RLN)(RLN)
! Sim’s triangle– Carotid artery– Trachea– Inferior pole of thyroid
! LRLN runs parallel with the TEG
! RRLN runs diagonal with the TEG
Thyroid gland Thyroid gland -- HistologyHistology
! Follicle:– functional unit– Follicular cells– Contains colloid
! Lobule: – 20-30 follicles
! Parafollicular cell or C-cell
PhysiologyPhysiology
! Euthyroidism control: 1. TRH (thyroid releasing hormone) and TSH (thyroid stimulating hormone)
2. Thyroid gland: synthesis, storage, secretion of thyroxine (T4), triiodothyronine (T3)
3. Peripheral control metabolism of T3, T4
Thyroid NoduleThyroid NoduleStatisticsStatistics
! 3%-7% population, female is 6.5%; male is 1.5%! 4% of these nodules are malignant, 1% of all
cancers! Male have a higher risk of being cancer! Single nodule is more likely malignant than
multiple nodules! Nodules in children and the elderly have a higher
risk of malignancy
History TakingHistory Taking
! Age, gender! Thyroid mass or nodule (time coarse, growth)! Associated symptoms
– Pain, hoarseness, dysphagia, dyspnea, stridor, hemoptysis
! Radiation, goiter, Hashimoto’s, Grave’s, other cancers.
! Family history of thyroid and other endocrine tumors.
Physical examPhysical exam
! Complete head and neck exam– Bimanual palpation of thyroid gland and
cervical chain of lymph nodes! Laryngoscope:
– Evaluate for vocal cord mobility and symmetry
DiagnosisDiagnosis
Needle biopsy: ! Core needle biopsy:
– Adequate tissue for diagnosis– Disadvantages
! more difficult! more traumatic ! more complications
DiagnosisDiagnosis
! Fine needle aspiration (FNA):– Easy to perform, less morbidity.– FN: 0.3-10%; FP: 0-2.5%– Disadvantages
! less tissue for diagnosis! limit in differentiation of certain types of thyroid
cancers– Follicular adenoma vs. carcinoma– Hurthle cell adenoma vs. carcinoma
DiagnosisDiagnosis--FNAFNA
DiagnosisDiagnosis
Blood test: ! T4,T3, TSH (thyroid function tests)! Ca, P (hyperparathyroidism asso. with TC)! TG (increase in recurrent WDTC)! Calcitonin (increase in MTC)
Diagnosis Diagnosis ––U/SU/S
! Sensitive (80%)! Detect nodule 2- 3 mm! F/u cystic asp., re-
collection of fluid! FNA guide.
DiagnosisDiagnosis-- ImagingImaging
! CT: ! Detect tracheal invasion! Evaluate for cervical met
! MRI! Useful to detect residual, recurrent and metastatic carcinoma. ! T2 differentiates tumor and fibrosis.
! CXR: ! tracheal deviation, airway narrowing, lung
metastasis.
Diagnosis Diagnosis –– thyroid scanthyroid scan
! Radioactive iodine or technetium uptake! Before FNA – test of choice for initial w/u! Uses today
– Indeterminate FNA– Large benign nodules (> 4cm)
Thyroid CancerThyroid Cancer
Classification: 1. Well-differentiated malignant neoplasms
(85% of thyroid cancer)*Papillary thyroid carcinoma (PTC)*Follicular thyroid carcinoma (FTC)*Hurthle cell carcinoma (HCC)
PathologyPathologyClassificationClassification
2. Poor differentiated malignant neoplasms*Medullary thyroid carcinoma (MTC)*Anaplastic thyroid carcinoma (ATC)*Insular thyroid carcinoma (ITC)
3. Other malignant tumors: *Lymphoma*Metastatic tumors
Papillary Thyroid Carcinoma (PTC)Papillary Thyroid Carcinoma (PTC)
! Most common WDTC - 75%-85% ! 80%-90% of radiation-induced TC ! Peak incidence: 30s-40s! 10 year-survival: 84%-90%! Female:male ratio is 3:1
PTC PTC –– pathologypathologyVariantsVariants
! Microcarcinoma! Macrocarcinoma! Encapsulated! Follicular! Oncocytic! Solid
! Diffuse Follicular! Diffuse Sclerosing! Tall Cell! Columnar! Dedifferentiated
PTC PTC -- pathologypathology
! Gross– Non-encapsulated– Central necrosis with fibrosis or hemorrhage– Cystic degeneration in large tumors– Multicentricity in 75% of tumors– High rate of metastasis to regional lymph nodes
(50%)
PTC PTC -- pathologypathology
! Histology– Psammoma bodies– Columnar thyroid
epithelial – Well-form
fibrovascular cores
PTC PTC -- pathologypathology
! Histology– Papillary projections– Nuclei
! Vesicular and ground-glass “Orphan Annie” appearance
! High N:C ratio! Mitotic figures
Follicular Thyroid Carcinoma (FTC)Follicular Thyroid Carcinoma (FTC)
! 5%-10% of thyroid cancers, 15% of WDTC! Peak in 50s! Female:male ratio is 3:1! 10-year survival rate: 86% in non-invasive
tumors, 44% in invasive tumors
FTC FTC -- pathologypathology
! Gross– Well-encapsulated– Cystic degeneration, calcification, hemorrhage– Tendency invade the thyroid capsule and blood
vessels.
FTC FTC -- pathologypathology
! Histology– Follicular pattern with
vesicular nucleolus cells
FTC FTC -- pathologypathology
! Histology– Capsular and vascular
invasion
HurthleHurthle Cell Carcinoma (HCC)Cell Carcinoma (HCC)
! Most aggressive type of WDTC! About 5% of WDTC! High incidence of bilateral thyroid lobe
involvement! High incidence of recurrence and high
mortality
MedullaryMedullary Thyroid Carcinoma (MTC)Thyroid Carcinoma (MTC)
! Account for 5% to 10 % of all thyroid cancers
! Tumor of the calcitonin-producing parafollicular or C-cells
MTCMTC
! Sporadic– 80% of MTC– Poorer prognosis– Unifocal– Not associated with other endocrine tumors– Peak in middle age to elderly
MTCMTC
! Familial – 20% of MTCs– Autosomal dominant inheritance– Associated with C-cell hyperplasia – Associated other endocrine tumors– Peak in 30s.
MTCMTCFamily traitsFamily traits
! Sipple’s syndrome (MEN II a) – MTC– Pheochromocytoma– hyperparathyroidism
! 2. Wermer’s syndrome (MEN II b) – MTC – pheochromocytoma– mucosal neuromas– marfanoid habitus.
MTCMTC
! 50% have regional metastases to lymph nodes.
! Distant metastasis include: lung, liver, adrenal glands, and bone (osteoblastic)
MedullaryMedullary carcinomacarcinoma
! Gross– gray to yellow, firm,
well-circumscribed or invasive with bilateral multicentricinvolvement.
! Histology– Hyperplastic C-cells
contain immunoreativecalcitonin
AnaplasticAnaplastic Thyroid Carcinoma (ATC)Thyroid Carcinoma (ATC)
! Undifferentiated differentiated CA! 3% of thyroid cancers! Most aggressive, poorest prognosis! Uncapsulated, extension out side the gland! Death in several months due to airway obstruction,
vascular invasion, distant metastasis.! Higher incidence in pre-existing multi-nodular
goiter
AnaplaticAnaplatic CarcinomaCarcinoma
! Gross– fleshy, tan-white
appearance, with hemorrhagic and necrotic areas.
! Histology– spindle or giant-cell
Malignant LymphomaMalignant Lymphoma
! 2%-5% of thyroid cancers! Increase in Hashimoto’s or endemic goiter
areas! Most common in > 50s ! Prognosis factors: cell types and stages
Malignant LymphomaMalignant Lymphoma
! Gross– large, yellow-tan,
scaly with hemorrhagic and necrostic areas
! Histology– small cell non-cleaved
type (MC) and large cell non-cleaved follicular
MetastaticMetastatic carcinomacarcinoma
! Found in 2%-4% of patients who died of cancer
! MC from: malignant melanoma, lung, kidney, breast, colon.
! Mets. by lymphatic or vascular deposits of tumor emboli
StagingStaging
Management of the Thyroid NoduleManagement of the Thyroid Nodule
Serial exam! Physical examination
– Benign– Asymptomatic palpable nodule
! U/S – F/u a benign, nonpalpable nodule– F/u a cystic nodule for reaccumulation
Management of the Thyroid NoduleManagement of the Thyroid Nodule
! Trial of suppression of TSH– Benign or indeterminate FNA (controversial)– Maintain TSH level between 0.1 and 0.5
mlU/L per day– Decrease tumor volume up to 50% in 40% pts.– A shrinking tumor is not likely malignant
Management WDTCManagement WDTC
Surgical options! Total thyroidectomy! Thyroid lobectomy
– benign or inconclusive frozen section! Near total thyroidectomy
– Preserve minimal thyroid tissue, RLN, parathyroid glands.
! +/- Neck dissection ! N0 – Elective neck dissection is not indicated for WDTC! N+ - Level II-V and VI neck dissection
Level I if clinically + nodes - rare
Management WDTCManagement WDTCAdjuvant therapy: ! Post-op radioactive iodine
– Total body scan to evaluate for residual and mets– If positive, I-131 ablation performed– Pts should be hypothyroid (TSH > 50 mU/l) prior to
scan– Patients are followed with yearly scanning X 5 years
! External beam radiation therapy– Advanced locoregional WDTC with gross residual– Tumors that do not pick up I-131 – Unresectable bone mets– More sensitive in follicular & papillary vs. Hurthle cell
.
Management Management HCCHCC
! Tx of choice is thyroidectomy! Thyroid lobectomy
– Adequate with benign frozen section– Completion thyroidectomy for indeterminate frozen
section malignant on final pathology! Tumors are unresponsive to external beam
radiation or I-131! Post-op thyroid suppression is indicated because
tumors have TSH receptors.
ManagementManagementMTCMTC
! Surgery: Thyroidectomy and SLND (level II, III, IV), anterior compartment ND (include level VI, and/or VII).
! 10-year survival rate is 90%! Recurrent MTC: resistant to chemo and
XRT
ManagementManagementATCATC
! Dx: FNA or open biopsy! Usually unresectable! Tracheotomy for airway obstruction! Tx with the combination:
* Surgery: thyroidectomy/ND, debulking surgery* Chemotherapy: Adriamycin and Cisplatin* XRT: only external beam, tumor does not
concentrate I-131,
Surgical complicationsSurgical complications
Non-metabolic complications ! Nerve injury
– SLN (laryngeal sensation) – up to 5% incidence ! Unstable voice! Diff. high pitch,! Dysphagia and aspiration! Laryngoscopy:bowing of VCs, ipsilateral rotation or
displacement of affected VC.– RLN up to 1-2% incidence
! Unilateral – no treatment vs medialization procedure ! Bilateral: re-intubate, tracheotomy
Surgical complicationsSurgical complications
Non-metabolic complications: ! Hemorrhage: thru the drains, neck swelling! Airway obstruction
– Hematoma– Laryngeal edema – Bilateral RLN injury
! Chyle leak! Pneumothorax
Surgical complicationsSurgical complicationsMetabolic complications: ! Hypocalcemia: 5% of thyroidectomy
– Prevention - autotransplatation of parathyroid glands– Treatment – IV vs PO calcium replacement and Vit. D
! Thyroid storm– More common in pts. with hyperthyroidism or chronic
systemic diseases! Tx. supportive! Beta blockers! Muscle relaxants
Prognostic factorsPrognostic factors
! Histology: is an important factor! Age: is a significant factor, e.g. WDTC! Sex: female have more risk of thyroid nodule;
males have more risk of thyroid cancer! Size: tumor > 1.5 cm has poorer prognosis! Extracapsular, vascular invasion or metastases
disease are poor prognosis factors! History of radiation: high risk of papillary CA
Prognostic factorsPrognostic factors
! Mayo clinic: “AGES” including age, grade, extracapsular tumor, and size.
! Lahey clinic: “AMES” including age, metastasis, extracapsular tumor, and size.
ConclusionConclusion
! Thyroid cancer is relatively rare (1% of all cancers), one of the most curable cancer.
! Surgery is the treatment of choice for most of thyroid cancers
! Preservation of the RLN and normocalcemia are the goals for a successful thyroidectomy
! Surgical complications are preventable and treatable
Thank you!!!Thank you!!!